One scalar-vector-tensor theory to unify dark energy, dark matter, and Hubble tension

By coupling a massive vector field to baryonic matter and a scalar field to the Jordan-frame metric, the model modifies the expansion rate that matter observers actually measure, boosting the effective Hubble constant without disturbing early-universe physics. The scalar potential drives dark-energy-like acceleration, while the vector field's density-dependent mass makes it behave as pressureless dust on cosmological scales. A chameleon screening mechanism suppresses deviations locally, keeping the theory consistent with precision Solar System measurements. The framework unifies three major open problems — dark energy, dark matter, and the Hubble tension — in a single Lagrangian, though observational confrontation beyond the phenomenological construction remains to be done.